An oil or gas well may use many types of apparatus that require an electric connection, such as tools and measuring devices that are lowered down the well, and equipment that is installed or present in a casing or production tube. Electrical power for these tools is usual supplied through a conductive line from the surface extending from the tool to the surface. Sometimes a conductive line must be disposed down the well to attach to the tool, rather than the tool being lowered with the conductive line already attached. There are many reasons why the conductive line is not always installed simultaneously with the tool; the tool may have been installed with or incorporated in the casing or production tube, or it may be convenient to install a particular tool down a casing or production line without an electric line, or an already attached electric line may have to be recovered due to a fault or to allow another tool access.
To make an electric connection in this downhole environment, it must be ensured firstly that the lowered connector locates and engages securely with the installed connector, and further that well fluid and material suspended in the well fluid does not penetrate between the surfaces of the connectors to prevent or degrade the conduction between the connection. Ideally, the connection should be reversible without damaging the connectors, allowing the lowered connection to be released and removed from the well, and re-lowered and re-attached as many times as necessary.
It is an object of the present invention to effectively protect the electric connection between the lowered and installed connectors.